Bulk Handling Conveyors Wiki
Welcome to the Bulk Handling Conveyors Wiki The history and technology progression of bulk handling conveyor. Introduction of Bulk Handling Conveyors This Wiki focuses on the seven main types of Bulk Handling Conveyors. Each conveyor is discussed with general design parameters and some vendors for each type. The information below provides a general idea of the different conveyors and mentions some unique vendor modifications. History of Bulk Handling Conveyors Bulk handling conveyors, is simply what its name states, a conveyor that handles bulk material. Bulk material is defined as a material that is “ordered, stored, issued, and sold by weight, volume, or footage“ "What Is Bulk Material? Definition and Meaning." Business Dictionary N.p., n.d. Web. 26 Feb. 2015.. To simply put it, bulk material usually deals with things that do not have a set quantity such as a pile of dirt or a bag of leaves as examples. There is no specific date when bulk handling conveyors were created. However, there is a date for the plain conveyor belt. Thomas Robins developed the first widely known conveyor belt, in 1892, to carry coal, ore, and other materials. "Product Know-how." N.p., n.d. Web. 26 Feb. 2015. The questions are what inspired the conveyor belt and how did it evolve to handle bulk materials? Knowing the material and the process that Thomas Robins was involved in may be clues to answer these questions. Previously stated, Thomas Robins developed a conveyor belt dealing with coal and ore. Knowing that coal and ore were involved, mining was probably the process Thomas Robins was involved with. Several equipment involved with transporting material or sifting through material from mines at the time before Thomas Robins were mine carts and sluice boxes, respectively. The picture shown to the left, shows miners in front of a sluice box. Even though the bulk handling conveyor does not have the same function as the sluice box, it can be seen that they look similar in appearance. Sluice boxes were used to separate gold from gravel by using gravity and running water Boxes 101." My Gold Panning. N.p., n.d. Web. 27 Feb. 2015.. The bulk handling conveyors could have been inspired by this process to improve the efficiency of transporting the gold and gravel. Similarly, mine carts could have contribute to the creation of bulk handling conveyor as well. Types of Bulk Handling Conveyors Bucket Conveyor Bucket Conveyors are a type of conveyors that handle bulky material. There are three categories that bucket conveyors are classified under and they are as followed: Gravity discharge bucket conveyors, pivoted bucket conveyors, and bucket elevators Ray, Sidharatha. Introduction to Materials Handling. New Age International, 2008.. Each category of the bucket conveyor will be explained in the following table. Screw Conveyor The screw conveyor gets its name for the spiral inside the conveyor trough. This spiral rotates which causes materials to move along the length of the conveyor. Screw conveyors are mostly used in bulk material applications when moving materials between dry and somewhat fluid "Screw Conveyors." Screw Conveyors. N.p., n.d. Web.. Also, these materials should flow similar to liquids when agitated Mecke, Bill. Choosing a Screw Conveyor to Handle Your Tough Material (n.d.): n. pag. KWS Manufacturing Co. Web. One particularly unique aspect of screw conveyors is they move material without using traction Tomašková, Marianna1, marianna.tomaskova@tuke.sk, and Juraj1, juraj.sinay@tuke.sk Sinay. "The Use Of Screw Conveyors In Practical Applications." Applied Mechanics & Materials 683 (2014): 225-231. Applied Science & Technology Source. Web.. Because screw conveyors move materials in such a manner, operators must be careful not to fill the cross section or they risk jamming the conveyor Tomašková, Marianna1, marianna.tomaskova@tuke.sk, and Juraj1, juraj.sinay@tuke.sk Sinay. "The Use Of Screw Conveyors In Practical Applications." Applied Mechanics & Materials 683 (2014): 225-231. Applied Science & Technology Source. Web.. The likelihood of this occurrence can be reduced by “choosing a single-flight ribbon screw” Mecke, Bill. Choosing a Screw Conveyor to Handle Your Tough Material (n.d.): n. pag. KWS Manufacturing Co. Web.. A possible alternative is using a shaftless screw conveyor developed by KWS "Shaftless Screw Conveyors." Shaftless Screw Conveyors. N.p., n.d. Web.. Though not all screw conveyors are horizontal. Conveyors can be designed to move material vertically or at an inclined angle Mecke, Bill. Choosing a Screw Conveyor to Handle Your Tough Material (n.d.): n. pag. KWS Manufacturing Co. Web.. Screw conveyors are fairly cost effective . Which such a flexible conveyor design, vendor variations are readily available for different situations. One such function design variation is simply enclosing the screw conveyor . This covering contains hazardous materials during processing . An additional option is to modify the spiral to chop products while being processed . Thus, screw conveyors lend themselves well to food industry applications. One particular example is a vertical screw conveyor that was tested for Nestle "Vertical Screw Conveyor Test for Nestle - Powdered Sugar." YouTube. YouTube, n.d. Web.Screw conveyors are good conveyor options that can be modified with food grade equipment. A final note, these conveyors can also cool or heat products by changing the conveyor housing design . With such variety, screw conveyors are widely applicable. For more details about suppliers for this and other conveyors, look into the Powder and Bulk Engineering organization. Vibrating Conveyor Vibrating conveyors are similar to oscillating conveyors except for one main difference. The difference is that oscillating conveyors operate at lower frequencies and higher amplitudes than vibrating conveyors. Holloway, Michael, Nwaoha, Chikezie, and Onyewuenyi, Oliver A., eds. Process Plant Equipment : Operation, Control, and Reliability. Somerset, NJ, USA: John Wiley & Sons, 2012. ProQuest ebrary. Web. 25 February 2015. When these conveyors are constructed their final shape ends up being in a trough (Figure a), tube (Figure b) or bed. They are most commonly constructed from stainless steel and powered by an unbalanced motor driven flywheel. "Conveyors." Material Handling Equipment Taxonomy. CICMHE, 30 Sept. 1999. Web. 26 Feb. 2015. Since the flywheel is unbalanced as it moves back and forth it creates the vibrations that power the conveyor. "Magnetic Belt Conveyor Systems." Dorner Conveyors. N.p., n.d. Web. 26 Feb. 2015. This type is unique among conveyors because instead of having a belt or roller move with the product, the components that make them up do not move with the product. The components stay stationary while the product “bounces” its way to the final destination. You would think that since the product is bouncing off the surface of the conveyor that this would be an inaccurate way of moving product, but this is not true. Vibratory conveyors move product accurately to where it needs to go . As far as operations are concerned, vibrating conveyors can be used to convey all granular, free-flowing material. They can be used in many operations including: screening, separating, sizing, metal removal, blending and drying. Since they have a broad application areas this type of conveyor is found in many industries including the food, chemical and rubber industry. There are several notable advantages and disadvantages of vibrating conveyors. One advantage is these conveyors tend to be extremely sanitary since they lack a belt, this has led to them being popular in the food industry. Another plus is that vibrating conveyors are incredibly reliable in terms of run time. Vibrating conveyor belts are also adaptable in their design; because of this they can be designed to fit onto tight space where normal conveyors could not fit and can also be used to move product up inclines and around corners. One major downside to vibrating conveyors is the cost. Both upfront cost and maintenance costs are high on this type of conveyor They also require precision when being set up, as a result each side of the conveyors must be balanced. This type of conveyor is also limited in how long it can be. A final draw back to vibrating conveyors is that the floor below them must be able to absorb the vibrations that are given off by them. Chute Conveyors Chute conveyors are some of the simplest conveyors available for purchase because of this they are also inexpensive. Some models do not even use electricity. McGuire, Patrick M. "9 Miscellaneous." Conveyors Application, Selection, and Integration. N.p.: CRC, 2009. 141+. CRCnetBASE. Web. 25 Feb. 2015 This is possible because of their design, chute conveyors are sloped and therefore can use gravity to move product. Chute conveyors can be ordered in steel or plastic and can be made either straight or curved. Stainless steel and straight are the most popular options. The size of these conveyors ranges anywhere from just a few centimeters to meters in length. This variation in size is useful because a main function of chute conveyors is to transfer product between different elevations. 2. When this product is transferred it will either end up being dropped off at a holding area or linked into another conveyor to travel to the next process step. A main area of application for chute conveyors is within shipping facilities. The packages will be moving along on a belt and then be dropped into the chute which either stores them sends them to the next destination. Industries where chute conveyors are commonly used include: chemical, pharmaceutical, and agriculture. They are also widely used within shipping facilities. There are several notable advantages and disadvantages of chute conveyors. One pro of this conveyor is the cost. These conveyors are cheap compared to other options. They also come in different materials ranging from steel to plastics. Another plus is these machines are able to handle bulk product such as granular material. A big disadvantages is that it is difficult to control the position of product as it moves through the chute. This can be problematic when dealing with large objects, but not granular material. Magnetic Belt Conveyor A magnetic belt conveyer is a specialized piece of machinery. This is in part due to how it works, but also because it is best used only with ferrous (iron containing) material. This type of conveyor is often found on the ground level with other bulk material handling equipment. The unique thing about magnetic belt conveyers is that they rely on magnets to transport material, this is why they are best used when ferrous material is involved. There are two main ways with how these conveyors work. The first is by having an electromagnetic rail underneath the belt and the second is by having rare-earth magnets under the belt, both options work in the same way which is they pull ferrous material to the belt so it cannot move. The primary uses of magnetic belt conveyors are to: transfer parts or scrap to and from stamping processes, move horizontally through elevation/corners and stacking/unstacking of ferrous objects. One thing about these conveyors is that the surface of them is sealed, this prevents dust and debris from finding its way into the inner workings. For this reason this type of conveyor is used often in the mining, construction, chemical, food, cement industries. There are several advantages and disadvantages to magnetic belt conveyors. An advantage to these conveyors is product can be easily removed from the surface. A big advantage is that this type of conveyor can be used in operations where the belt needs to run upside down, this is useful for separating material (see below figure) . Another advantage is that when looking for one it is possible to pick both the size and strength of the magnets which allows a conveyor to fit a niche in production settings. This type of conveyer can also transport product over steep inclines and curves. Scott, Paul, and E. E. Hubbard. "What Is a Magnetic Conveyor?" WiseGeek. Conjecture, n.d. Web. 26 Feb. 2015. There is one fundamental disadvantage to these conveyors and that is spillage. When the material being transported is not ferrous it will fall off. This make the magnetic belt conveyor a specialized conveyor. This type of conveyor is also more expensive than traditional conveyors. Troughed Conveyor Troughed conveyers are unique because when they are loaded the belt conforms to the shape of the trough verses other types of conveyors where the belt shape is fixed. However the return side of belt is often kept flat. This type of conveyer is also almost used exclusively in bulk handling applications range from moving ore and coal to dog biscuits and crackers. McGuire, Patrick M. "Chapter 4. Belt Conveyors." Conveyors Application, Selection, and Integration. N.p.: CRC, 2009. 62-66. CRCnetBASE. Web. 25 February 2015. This type of conveyor can also be very large. In fact the largest trough conveyer in 9.5 miles long and is located in KweKwe, Zimbabwe. The troughed conveyor gets its U-shape from an arrangement formed by series of alternating horizontal and inclined rollers. These rollers are cylindrical and can rotate freely. The size of rollers ranges from as small as 1.9 inches to as large as 7 inches in diameter, the environment is a big factor when choosing a size. The belts on trough conveyors are often the most expensive part and they are also the most frequently stocked spare part. As one can expect there are both advantages and disadvantages to trough conveyors. A big advantage is these conveyors can move more volume of product than a belt of equal width. Another advantage is they can be adapted to the environment, this means that they can go up and down hills and stretch for thousands of meters. Trough belt conveyors also come in a variety of angles with the most popular being 20, 35 and 45 degrees, this versatility allows for more customization. The biggest disadvantage of trough conveyors is they have no regard for product orientation. This means that are best used in operations like mining. Pneumatic Conveyor A Pneumatic conveyor is a tube system that uses pressure to either pull or push material through the system "Conveyors." Conveyors. N.p., n.d. Web.. This system can have multiple entry and discharge points and may use a combination of pressure and vacuum to move material . The tube system can be vertical or horizontal and use air or some other gas to move materials "A Quick Look at Pneumatic Convey Systems Basics." Dilute Phase vs Dense Phase Conveying Overview. Nol-Tec Systems, n.d. Web.. Pneumatic conveying allows materials to move easily around corners and through a facility . Also, there are fewer moving parts to the pneumatic conveyor compared with a mechanical one . The aforementioned advantages are possibly highly desired for certain applications. However, there are some major disadvantages in relying pressure to move materials. A particularly strong issue is the pneumatic system is best for products that have smaller dimensions and are not sticky . Pneumatic conveying has two main phases; Dilute and Dense . Dilute phase conveying keeps product floating in air at a high velocity . This phase is mostly used for powders and other light density materials . Also, dilute phase is especially good for moving product with multiple sources into one destination . For a video about dilute phase, look into Vacuum Dilute Phase by Powder-Solutions Group "Vacuum Dilute Phase." YouTube. YouTube, n.d. Web. Feb. 2015.. This only shows a vacuum set up but is by no means the only source on dilute phase systems. Dense phase is almost the complete opposite of dilute phase. In dense phase, particles travel at a much lower velocity but uses a higher pressure . Fragile and abrasive materials do best in the dense phase conveyors and short distances . For a video about dense phase, look into Pneumatic Conveying TPA Line by Air-Tec System "Dense Phase Pneumatic Conveying TPA Line - Air-Tec System." YouTube. YouTube, n.d. Web.. With the variety of powders that could be processed with the Pneumatic system, there is a wide variety of properties for each type. The properties then require specialized conveyor systems to handle the products correctly and in the most efficient manner. The range of materials is expansive; from shredded cheese, pet food, to burnt wood chips, and gypsum "Powder-Handling Solutions: Feeding and Pneumatic Conveying Systems for the Process Industries." Powder-handling Solutions the World's Process Industries. Coperion K-TRON, n.d. Web.. Looking at a specific example: food and pharmaceutical, it is highly important to develop sanitary conveying. This requires dust free metal systems with sophisticated controls "Pneumatic Conveying Components for Vacuum and Pressure Conveying Applications." Pneumatic Conveying Systems Overview. Coperion K-TRON, n.d. Web. Feb. 2015.. The system will likely be a dense phase system for the delicate food pieces . Also, the system will need to be highly accurate using precise and multiple weighers . There are a large variety of companies supplying these pneumatic conveyors. One such company is Coperion k-TRON . Another major company is Flexicon who offers a similar variety as Coperion k-TRON. One key point on Flexicon is many of their designs focus self-contained and mobile equipment "BULK HANDLING EQUIPMENT & SYSTEMS." Pneumatic Conveyors. Flexicon, n.d. Web. Feb. 2015.. Another company is Pneumatic Conveying, Inc. Pneumatic Conveying, Inc (or Pneu-Con) specializes in food, chemical. Mineral and plastic industries "Pneumatic Conveying, Inc. / Pneu-Con." Pneumatic Conveying Systems, Pneu-Con Bulk Material Handling Solutions. Pneumatic Conveying, Inc., n.d. Web. Feb. 2015.. With their specialization, Pneu-Con has created registered products with unique trademarked names like “Powder Whisper Loaders” . A video of interest with a test using granular sugar in a pneumatic conveyor "Granular Sugar Pneumatic Conveying Test." YouTube. YouTube, n.d. Web. Feb. 2015..This video shows flexible tubing that is transparent enough to show how the sand moves through at the different heights and curves. References Activity Feed Category:Browse